ract bigraphs lack RPOs 57 6 Sorting 59 6.1 Place sorting and CCS 59 6.2 Link sorting, arithmetic nets and Petri nets 64 6.3 The impact of sorting 69 Part II : Motion 71 7 Reactions and transitions 73 7.1 Reactive systems 74 7.2 Transition systems 77 7.3 Sub transition systems 84 vii © Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-73833-0 - The Space and Motion of Communicating Agents Robin Milner Table of Contents More information